According to the New York Times, Nichole Ward and her classmates were tasked with finding out just how much bacteria would grow in various unsterilized locations after setting down a petri dish there for three minutes. Ward decided she'd put hers inside a Dyson hand dryer in the women's bathroom and quickly discovered her spot was much grosser than all her other classmates'. In a viral Facebook post, the California woman displayed a photo of the truly horrifying arrangement of fungi that was apparently lurking inside the ubiquitous machines.

"DO NOT EVER dry your hands in those things again," she wrote. "This is the several strains of possible pathogenic fungi and bacteria that you’re swirling around your hands, and you think you’re walking out with clean hands. You’re welcome."

The swarm of commenters seemed either vindicated or completely outraged by the post, with some blaming the dryers for making people sick and others claiming that Ward is being deceptive or unscientific. Ward told the Times she's even received some death threats.

But mostly, the post has tapped into a years-long war between the paper towel and hand dryer industry about which product is more sanitary. Big Dryer already clapped back at the viral post by questioning Ward's methodology, which is exactly what it did in 2016, when a university study concluded that their machines spread bacteria. After VICE wrote about that study, a representative from Dyson emailed to say that "the paper towel industry has scare-mongered with this research for the past four years." (The Times notes that one of the only independently funded studies into the matter found that paper towels and hand dryers were mostly hygienically equivalent.)

But until scientists decide one way or the other, it might make sense to just wave your hands around or wipe them on your jeans after washing them.